Recommended materials for the heating furnaces in distillation units for processing high-sulfur, high-acid crude oil in refineries

Well, in simple terms: when refineries process crude oil with high sulfur and acid content, the following materials are recommended for the furnace tubes in the heating furnaces: * **Convection section**: In most cases, **1Cr5Mo**, a heat-resistant and sulfur-resistant steel, is used. * **The last few rows of furnace tubes at the exit of the convection section**: Since the temperature is highest here, corrosion is more severe; therefore, better **0Cr17Ni12Mo2** (i.e., 316 stainless steel) has been used in place of the existing material to resist corrosion caused by high temperatures, sulfur, and acids. * **Radiation section**: There are several options available, depending on the specific operating conditions and budget: * **1Cr5Mo**: A basic choice, offering heat resistance and sulfur resistance. * **Aluminized 1Cr5Mo**: A layer of aluminum is applied to the surface of 1Cr5Mo, which significantly enhances its resistance to high-temperature sulfur corrosion, offering good cost-performance. * **0Cr17Ni12Mo2** (316 stainless steel): The highest-grade version, with the best corrosion resistance, and is used in the most demanding applications. **To sum up: **The key principle is to use the best materials where they are most needed; in areas with the highest temperatures and greatest corrosion risk (such as the outlet of the convection section and key parts of the radiation section), higher-grade stainless steel (316) or furnace tubes treated with aluminum infiltration is used to ensure the safe and long-term operation of the equipment.** .